An advanced Giemsa C-banding technique for the chromosomes of gymnospermous plants has been developed by modifying the method of the conventional Giemsa C-banding. It was found that the best procedure so far obtained to separat C-banded chromosomes well was: (1) pretreatment; (2) fixation; (3) maceration; (4) squashing; (5) air drying; (6) treatment with 5% barium hydroxides; (7) treatment with 4X SSC and (8) Giemsa staining. All three species stutied i. e. Cunninghamia lanceolata, Larix gmelini and Pinus sylvestris var. mongolica showed clear C-banding in the interphase and metaphase chromosomes. the three species were found to be different from each other phylogen-etically in respects of the number and occurrence of the pericentromeric, intercalary and telomeric (satellite) C-bands. The idiograms of their C-bands were summarized as follows:C. lanceolata: 2n=22=10(O/P)+10(P/O)+2((PT)/O)L. gmelini: 2n=24=8(O/P)+10(P/O)+2(I/P)+2(P/I)+2(P/P)P. sylvestris var. mongolica: 2n=24=8(O/P)+4(P/O)+4(O/(OP))+4(P/I)The procedure described above provides a highly reproducible C-banding technique for distinquishing unequivocally the metaphase chromosomes. The C-banding condition in the chromosomes and the nature of the heterochromatin exhibited were also discussed in the present paper.

In this paper the feature of transmission of direct light in plantation of Cunninghamia lanceolata in Huitong county was described and discussed, according to the theoretical distribution and observational data in 1982—1988. The results obtained are summarized follows:1. The direct radiant flux on the surface of canopy at southern slope is larger than that at eastern and western slope, and it is smallest at northern slope.2. The slope gradient has a great influnce on direct radiant flux on forest floor. It decreases as the slope gradient increases, except southern slope. The decrement of direct radiant flux is largest at northern slope. It shows complicated feature at southern slope. In winter half year, it increases as the slope gradient. But in summer half year, it is reversed.3. The transmissivity of direct radiant or it's flux on the forest floor decreases, under an exponential manner, as the leaf area index increases. The transmissivity of summer half year is larger than winter half year.

In order to find out the quantitative method of protection and management of forest resources, the writers collected the investigative data of Picea and Abies population in Yeliguan Forestry Farm in 1983. Applying a method of mathematical statistics, the Logistic Equation of protection and management of forest resources in the area have been established, the computative method have been obtained. With these for forecasting, retaliating, determining quantitative maturity and cutting cycle were successful.

Leaves with systemic symptoms of ring or irregular spots and deformation (P-Ⅰ), and rolling leaves with yellowing inter-vein (P-Ⅱ), were collected from Hainan province and Beijing. The infected young leaves were triturated in a mortar with a pestle in 0.01M sodium phosphate buffer(pH7.2) containing antioxidate of 0.1% diethyldithioca-rbamate. The sap can infect both Nicotiana tobacum and N. tobacum cv. Xanthi-nc. And other herbaceous plants could also be infected with the two bridge hosts by mechnical transmission.Based on the morphology of the particles, serological reactions, physical properties and symptoms on differential hosts, P-Ⅰ and P-Ⅱ were considered to be CMV of Cucumoviruses and TMV of Tobamoviruses, signed by the symbol CMV-Pa and TMV-Pa, respectively.

The China fir borer, Semanotus bifasciatus sinoauster Gressitt has been treated as a subspecies of the juniper borer, Semanotus bifasciatus bifasciatus Motschulsky since 1951. During 70' s a great deal of works were done in combat with these borers in twelve provinces of China. All faetsrevealed that the southern subspecies differes from the nominate subspecies in host preference, the former is injurious to China fir while the latter to juniper, and the juniper log trap is effective to the latter subspecies, but not to the former subspecies. The geographical distribution is different, the former is predominant in south China, while the latter in north China, but there is a wide overlapping district in eastern to southwestern China. In addition, cross hybridization test between the two synpatric populations showed hybrid incapatibility and sterility.The authors performed a series of comparative study on the external morphology and on the anatomy of male genitalia and female ovipositor and speratheca. The detailed descriptions and measurements showed significant distinctions between these two kinds of borers. The authors suggest that they should be two different species, the taxonomic position of the China fir borer should be raised to species rank, and the scientific name should be revised to Semanotus sinoauster (Gressitt).

Destruction by termites to living tree trunk is generally negligible and not recorded in Guizhou Province. In this paper, five new species belonging to the genus Glyptotermes and Coptotermes are reported from living trees, Prunus persica, Liquidambar formosana, Ficus microcarpa etc. The latex termite Coptotermes is very destrective to living tree-trunk. The comparison of the new species are given as the following. All measurements are in millimeters. All the type specimens are kept in the Guangdong Institute and a part of the paratype specimens deposited separately in Guizhou Institute of Forestry.1. Glyptotermes guizhouensis Ping et Xu, sp. n. The soldier of this new species has a narrower and longish head-capsule which may be easily distinguished from all the species of head-width 0.08—1.10 hitherto found in China. The soldier resembles that of G.almorensis Gardner from India in the head-width. But G. almorensis has a shorter head, head-width index 0.65-0.75 and thicker mandible, length of left mandible 0.67—0.77. Type locality: Rongjing County (25°N, 108°E). Soldiers (holotypeand paratypes) nymphs from type-series (I. No. E 7768). Collected by Xu Chungui et al. May 30, 1983 in tree (Ficus microcarpa)2. Glyptotermes succineus Ping et Gong, sp. n. The soldier of the new species resembles that of G. latithorax Fan et Xia in the body size. It differs as follows: 1. Pronotum narrower, width 1.03—1.10, distinctly narrower than the head; instead of broader, width 1.22—1.37; distinctly broader than the head. 2. Posterior margin of postmentum nearly concave instead of convex. 3. Mandibles shorter than half the head-capsule instead of longer.Type locality: Libo County (25°N, 107°E) Soldiers (holotype and paratypes) nymphs from type-series (Ⅰ. No. E 7730). Collected by Gong Cai et al. Jun. 8, 1983 in wind breakage tree.3. Glyptotermes ficus Ping et Xu, sp. n.The soldier of the new species resembles that of G. hesperus Gao et al. in the head-width. It differs as follows: 1. Headcapsule shorter, length of head-capsule 2. 20 intend of 2.35—2.51. 2. Anterior area ofpostmentum nearly square instead of trapezoid. 3. Posterior margin of pronotum in middle slightly notched instead of not notched. 4. The length of hind tibia 1.04—1.10 instead of 0.90—0.96.Type locality: Rongjinang county (25°N,108°E) Soldier (holotype and paratypes) and nymphs from type-series (Ⅰ. No. E 7715) Collected by Xu Chungui et al. May 31, 1983 in tree (Ficus microcarpa) 4. Coptotermes ochraceus Ping et Xu, sp. n.The soldier of this new species can be easily distinguished from the know China species C. formosanus Shiraki by its opening slope of frontal gland in profile view is oblique. It resembles C. havilandi Holmgren, but its width of pronotum 0.90—1.02 instead of 0.70—0.85.Type locality: Xingyi County (altitude 700m, 25°N, 105°E). Soldiers (holotype and paratypes) and workers from type series (Ⅰ. No. T 5008).Collected by Ping May 22, 1979 in living tree (Prunus persica).5. Coptotermes rectangularis Ping et Xu, sp. N.The soldier of this new species can be easily distinguished from the known China species C. formosanus Shiraki by its: 1. The length of left mandible generally 0.95. 2. The length of head to lateral base of mandibles generally 1.43. 3. The width of pronotum 0.75.Type locality: Congjiang County (25°N, 108°E). Soldiers (holotype and paratypes) and workers from type-series (Ⅰ. No. E7690). Collected by Ping et al. May 28, 1983 in tree (Liquidambar formosana).

Through study on C-13 NMR and chemical analysis of Urea-Forma-ldehyde Concentrates (UFC), it is clearly shown that (1) UFC is a solution of formaldehyde, additive compounds of urea and formaldehyde, and prepolymer with low degree of polymerization and linkage of dimethylene ether (—CH₂OCH₂—), in which tri- and disubstituted urea are in the majority and tetra- is in the minority; (2) C-13 NMR of UFC supplies a quantitative determination to agree with that of chemical analysis, and more information about the constitution of UFC than it.

This paper is a study on chromosome banding technique of G-band. The somatic cells (root tip) of Cunninghamia lanceolata are used. After treated by the colchicine and fixed, the roots are zymolysed, dissociated and made into cell suspend material. They are, then, titrated and dried, throwgh the procedure 0.2 N HCL→0.00175M NaOH→(NH₄)Fe(SO₄)₂·12 H₂O→Giemsa, the G-band are shown.Afterwards, Pinus massoniana and Aleurites fordii are used respectively in the experiment, the same result are gotten as well.

Morphology of mesophyll cells was studied for some important species of bamboos distributed in Fujian province by Tuan's method of separating cell and microphotography.It is found that most of the mesophylI cells of bamboos are differentiated into complex cells with peaks, dales, isthmus and rings.Mesophyll cells of bamboos are in various shapes. Roughly, these cells can be divided into three types. The first, mesophyll cells have rings on one side; the second, rings on both sides (symmetric or asymmetric); the third, are in irregular shape.Mesophyll cells of leaves on the top of crown are larger than those of leaves on the lower part of crown for the some plant.It is showed that there are some variations in the area of surface and rings between individul cells for some species, and also cultivated species with monopodial rhizome and inflorescence have larger mesophyll cells than the wild with sympodial rhizome and pseudoinplorescence.

A key of afforestation in vast sand areas of China is moisture, which is why the relations between xerophyte and water have been considered as one of most important subjects in fixed positions since the establishment of Deng-kou Experimental Station in 1979. The water supply and consumption as well as physiological conditioning function of plants in draught environment are known by analysis of dynamic characteristics of groundwater that is reliable for plant living in sand areas and measurement of main plant physiological index-plant transpiration, water potential and adhesive water. Then suitable environment planting Haloxylon ammodendron and Hedysarum mongolicurn are determined. The research suppliss scientific data for classification of sites and selecting tree species in dry sandy areas also.

According to the data from the experiments, the author deals with the differentitating, tending and intermediate cutting of Luzon pine (Pinus kesiya var. longbianensis) in the standard lands. The research results indicate that the growth differentiation of Luzon pine is most striking during the young and middle growth of 6—15 years, and the growth would become stable when the stand is close to its mature age of 25 years. The change of its root system happens simultaneously with that of those parts above the ground. With regard to the mode of tending and thinning, it would provide better resoults to apply lower story thinning during young growth, overall thinning during middle growth, and to employ upper story thinning when the stand is drawing near to its maturity. The mixed growing of Luzon pine with hardwood would produce certain positive effect on soil reservation, soil amelioration, and on preventing plant diseases and insect pests.

In 1981, the NPV of Aporia crataegi was first discovered in Harbin, Heilongjiang Province, China. Since the mortality is height, the NPV has certain value in the biological control of Aporia crataegi.The inclusion body is spherical, cubic or irregular, with a diameter of 1.0—2.1μm. Each virus bundle consists of 1—12 virus particles. The virion is rod-shaped with a size of 260 40nm.A bioassay of the NPV on 3rd and 4th instar larvae has shown that LC₍₅₀₎ of 3rd instar larvae is 1.4×10³PIB/ml; y=3.472+0.488x. LC₍₅₀₎ of 4th instar larvae is 3.4×10⁴; y=3.212+0.395x.In the field, NPV was sprayed with a concentration of 10⁴, 10⁶, 10³PIB/ml to control the 4th and 5th instar larvae. The results indicated that the mortality is 71.4%, 90% and 100% respectively, while the natural mortality of the virus disease is 12.7%.

Release of artificial Trichogramma to control the pine caterpillar Dendrolimus punctatus Walker has been taken since 1980. The treated area of pine stand of field experiment was increased to about 1,000mu in 1984. The results of the experiments showed that the area of pine stand treated with artificial Trichogramma and with natural Trichogramma gave significant egg parasitism of 51.17+8.6% and 49.51±14.15% respectively. Both of them were much better than that of untreated check. That was 1.5±1.98%. So that the capacity of host location and parasitic effectiveness of artificial Trichogramma were comparable and in some respects superior to natural Trichogramma.Some characteristics of the artificial Trichograrnma were investigated at the same time: (1) Preferences for different vertical altitude of the host plant (pine); and (2) preferences for lower versus upper parts of the tree.

The study on the effective accumulated temperature of the pine caterpillars is a method for the prediction of emergence period. The result of the study is given in the following table.

A mean fibril angle of Pinus massoniana is measured by means of. Polarized-light microscopy. Single cell walls of wood fibers are halffibers produced by maceration of microtomed wood tangential sections. The mean fibril angle of latewood tracheids is smaller than that in the earlywood tracheids, and the mean value of sapwood is larger than that in the heartwood too. The mean fibril angle measured by polarized-light microscopy agrees well with the values obtained by iodine staining and X-ray (002) diffraction. It shows that the technique for measuring fibril angle using polarized light is feasible.

This paper introduces a wood identification system via microcomputer. The methods of sorting identification, using index table identification and inquiring about characters from specimen's Latin name are described. The great rate identification expounded emphatically by the authors works through a index table of "The Most Useful Character"——having least generality. The time for search takes a few seconds. 1 minute at longest. The procedure and programming idea of using microcomputer to distinguish woods are discussed.

Through a dynamic analysis of transverse vibration of a log truck with trailers, the author put forward a theoretical formula on transverse vibration of the truck. Every roof of the characteristic equation made from the vibration system indicates a movement with a formula of φ=A_ie^λt, which provides a possibility for us to seek for the dynamic stability. From the factors studied in this paper, the author concludes that any form movement is relevent to the structural dimension of the truck, such as the length of the trailer, the length of the pulling rod, the wheelbase, the location Of the centre of gravity, etc. The best structural dimension of the trucks can be found out based upon the dynamic theories.